uniform sampler2D tex1;
uniform sampler2D tex2;
uniform vec2 windowSize;

void main (void)
{
    vec2 screenCoord = gl_FragCoord.st;
    screenCoord.x /= windowSize.x * -1.0; 
    screenCoord.y /= windowSize.y;

    vec4 tex1Col = texture2D (tex1, screenCoord);
    vec4 tex2Col = texture2D (tex2, gl_TexCoord[0].xy);


    gl_FragColor = tex1Col * tex2Col; 
}
